Firearm accessory for attachment to muzzle of barrel



J. H. RUTH Nov. 3, 1964 F'IREARM ACCESSORY FOR ATTACHMENT TO MUZZLE OF' BARREL Filed April 18. 1962 INVENTOR f ATTORNEYS' United States Patent 3,155,003 FMEA ACCESSURY FOR A'I'TACHMENT 'EQ MUZZLE l? BARREL .lohn H. Ruth, 229 Lawrence St., Columbia, Pa. Filed Apr. 18, 1962, Ser. No. 188,388 lll Claims. (Ci. SSL-lift) This invention relates to a firearm accessory and more particularly to a firearm accessory capable of providing increased projectile velocity and improved accuracy through greater firearm stability.

The firearm art is both an ancient art and an art which has been considered and studied to varying extents by a large number of artisans and quasi-artisans who brought to bear upon the problems involved widely differing degrees of technical understanding .and ability. As a result, the art is replete with a wide Variety of gun barrel accessories intended to accomplish a number of different purposes. By far the majority of such devices have been primarily designed to act as muzzle brakes which reduce the recoil produced by firing of the weapon. A number of devices of this type have been marketed commercially. A far lesser .number of such devices have been intended to produce increased firearm accuracy and, so far as is known, very few of these have ever achieved any modicum of commercial success.

When a projectile or bullet is red through the barrel of a firearm, the propellant exerts tremendous pressure due to the release of energy through transformation from the solid to a gaseous state. Two types of gases are created in this conversion of energy, the `white hot or completely burned socalled white or working gases on the one hand, and the partially burned, turbulent so-called dark gases on the other hand. Both types of gases exert a propelling eiect upon the projectile or bullet while it is restricted to and within the confines of the firearm barrel and at this stage both types of gases might be said to be performing a useful function. However, the moment the projectile leaves the contines of the barrel it strikes a wall of atmosphere and is subjected to a shock which the projectile must absorb without losing accuracy if optimum performance is to be achieved. At this point the two types of gases exert quite different influences upon the projectile and must be looked upon as possessing widely varying degrees of usefulness.

The white hot and completely burned gases continue to propel the projectile and impart stability to it. The dark gcses, on the other hand, are of -a turbulent nature and tend to be uncontrolled in shape. As a result, these dark gases tend to impart instability to the ilight of the projectile. In addition to this, the dark gases contain partially burned particles of propellant and tend to absorb energy from the white hot or working gases in such a manner as to decrease the useful velocity of the projectile. The dark gases at this point exert an additional undesirable aifect in that they also tend to affect the white hot propelling gases by causing them to exent uneven and unstabilizing pressures upon the projectile.

According to the present invention there is provided a firearm accessory which controls and partially removes the dark unburned gases in such a way that their detrimental iniiuences on the white hot or propelling gases and on the projectile are greatly diminished. Moreover, at least a portion of the energy contained in the dark unburned gases is converted into a useful form for propelling and stabilizing projectile.

In order to accomplish these purposes, the iirearm accessory of the present invention provides a first controlled expansion chamber immediately forward of the muzzle of the gun barrel for providing a limited and initial controlled expansion of the gases as the projectile leaves the gun barrel and enters the accessory. Following this a first plurality of oppositely disposed ports effects a first controlled skimming of of dark gases from around the white gases without permitting an uncontrolled meeting of the gases with the atmosphere. The rearm accessory then provides a short controlled volume chamber which confines the gases until they reach a second plurality of oppositely disposed ports which are larger than the iirst ports and which permit the gases to undergo their first uncontrolled meeting with the atmosphere. Again a portion of the dark gases are skimmed or siphoned off and at the same time the white or working gases are permitted to expand outward. Following this second plurality of ports the gas following the projectile consists essentially of true white working gases which then enters a second controlled volume portion of the accessory where essentially only the true working gases are allowed to propel the projectile. A decreased diameter portion or construction of the accessory is next provided in order to skim the remaining vestiges of dark gases and the remaining white gases then enter a cone-shaped area to perform their iinal stabilizing function. From this point on the projectile is in free atmosphere and the white gases exert a steady propelling force.

The firearm accessory device of `the invention by thus performing a siphoning and controlled expansion effect stabilizes the propelling gases and the projectile to provide improved firearm accuracy. The device simultaneously reduces recoil, imparts greater velocity to the projectile, decreases barrel vibration, reduces muzzle flash and suppresses muzzle blast. Because of the shape, number and position of the ports, maintenance of the accessory is practically non-existent so that its effectiveness remains substantially undirninished as it is used over an extended period of time.

it is accordingly a primary object of the present invention to provide an improved firearm accessory which produces increased rearm accuracy.

It is another object of the invention to provide an irnproved firearm accessory which, in addition to increased firearm accuracy, also provides reduced recoil, increased projectile velocity, decreased barrel vibration, reduced muzzle tiash and suppressed muzzle blast.

lt is another object of the invention to provide an improved firearm accessory which produces increased tirearm accuracy through a unique control and utilization f the different types of propelling gases.

It is another object of the invention to provide an improved rearm accessory which achieves the foregoing objects through a unique handling of the dark propelling gases in such a manner as to not only decrease their unstabilizing effect but to also enable them to perform a useful function after the projectile leave-s the firearm muzzle.

It is still another object ofthe invention to provide a firearm accessory which provides in sequence a rst controlled expansion chamber immediately forward of the muzzle of the gun barrel for providing a limited and initial controlled expansion of the gases as the projectile leaves the gun barrel and enters the accessory; a first plurality of oppositely disposed ports for effecting a rst controlled skimming off of dark gases from around the white gases without permitting an uncontrolled meeting of the gases with the atmosphere; a short controlled volume chamber which confines the gases until they reach a second plurality of oppositely disposed ports which are larger than the first ports and which permit the gases their first uncontrolled meeting with the atmosphere whereby a portion of the dark gases are skimmed off and, at the same time, the white gas is permitted to expand outward; a third controlled volume chamber where essentially only true working gases are allowed to propel the projectile; a decreased diameter portion or construction of the accessory which skims the remaining vestiges of the dark gases; and an outwardly opening cone-shaped area to perform a final stabilizing function.

It is a still further object of the invention to provide a firearm accessory for a firearm having a barrel containing a bore which comprises a housing defining a central cylindrical chamber adjoining a reduced diameter chamber or construction at one end of the housing, which end of the housing opens to the atmosphere, the other end of the housing being open and adapted for attachment to the barrel of the firearm, the diameter of the central chamber being greater than the diameter of the bore of the firearm, with the central chamber being provided with a first pair of oppositely disposed ports centrally disposed about an axis perpendicular to the axis of the bore, and a second pair of oppositely disposed ports disposed centrally about an axis parallel to the axis of the first pair of ports, the first pair of ports being of smaller area than the second pair of ports and disposed between the second pair of ports and the other end of the housing.

These and further objects and advantages of the present invention will become more apparent upon reference to the following description and claims and the appended drawings wherein:

FIGURE 1 is a plan view of one embodiment of the present invention;

FIGURE 2 is a side elevation view of the embodiment of FIGURE 1;

FIGURE -3 is a cross-section taken along the line 3-3 of FIGURE 1;

FIGURE 4 is a vertical elevation along the line 4-4 of FIGURE 1; and

FIGURE 5 is a cross-section taken along the line 5-5 of FIGURE 2.

Referring now `to the several figures wherein like parts are given the same reference numeral, the firearm accessory generally indicated at 12, is affixed to the end of a firearm barrel, generally indicated at 10, in any wellknownV manner or it may be made an integral part of the firearm barrel. By way of example only, the firearm accessory 12 may be attached to the firearm barrel 10 by tapping and setting, brazing, welding or soldering, or by any other. well-known attaching means such as, a bayonet type locking joint. The accessory 12 is basically a hollow cylinder having an inner wall 13 which defines a central chamber, an outer wall 15 and oppositely disposed ports orv'ents 16, 32, 20 and 36. One end of the accessory 12 is attached, as above mentioned, to Lthe barrel 10V and the other end 30 opens into the atmosphere.

The barrel 10 comprises an outer wall 8, an inner wall 11 which forms a rified bore, and a vertically extending sight 4. The diameter of the bore of barrel 10 is less than the inside diameter of inner wall13 of accessory 12 whilerthe outside diameter of the barrel 10 is larger than the inside diameter of the inner wall 13 of accessory 12,

` but .less than theY outside diameter of the accessory.- The dimensions ofthe accessory 12 and related elements will be Ydiscussed in detail hereafter. Y

n. The oppositely disposed ports 16 and 32 open4 outwardly and are centered on an axis perpendicular to the longitudinal axis of the accessory. Since ports or vents 16 and 32 are identical, only vent 16, which is shown in FIGURES 2 and 3, will be described in detail. Vent 16 is a frustum of a hollow elliptoid which comprises an outer peripheral elliptical edge 19, an inner peripheral circular edge 17, and an elliptoidal striking surface 18 which connects the inner circular edge 17 with the outer elliptical edge 19. Located forward or to the right of vents 16 and 32 (see FIGURES 1 and 2) are vents 20 and 36 which also open outwardly and are centered on an axis parallel to the axis of the vents 16 and 32. Since vent 20 is identical to vent 36, only vent 20 will be described in detail. Vent 20 is also a frustum of an elliptoid which comprises an elliptical outer peripheral edge 23, an elliptical inner peripheral edge 21 and an elliptoidal striking surface 22 which connects edges 21 and 23.

The outer elliptical edge 19 of vent 16 has a major axis which is transverse to the longitudinal axis of the accessory 12 and a minor axis which is parallel to the longitudinal axis of the accessory 12. The axis of rotation of circular edge 17 is horizontal and is also perpendicular to the longitudinal axis of the accessory 12. The major axes of both elliptical edges 21, and 22 of vent 20 are parallel to the longitudinal axis of accessory 12 while the minor axes of both edges are transverse to the longitudinal axis of the accessory.

The left end of accessory 12 which engages barrel 10 has a counterbored portion 5 whose inner wall 9 receives the outer wall 8 of barrel 10 in the illustrated embodiment of the invention. Suitable set screws (not shown) may be used to fasten the accessory to the barrel. Inner walls 9 and 13 of accessory 12 form a shoulder 7 which abuts the end 6 of barrel 10. The inner wall 11 of barrel 10 and the inner wall 13 of accessory 12 form achamber 14. Chamber 14 constitutes a controlled expansion chamber for the propellant gases which surround and follow the projectile 2 when it leaves the barrel 10.

Referring now to the right end of accessory 12., there is shown a cylindrical constriction or throat 27 which has an inner cylindrical surface 28, the inner edge of which is connected to a conical surface 26 and the outer edge of which is connected to a conical opening or mouth 30. The outer or right end of inner wall 13 of accessory 12 is connected to conical surface 26 and forms a chamber 24, the purpose of which will be discussed in detail here-YV after.

Briefly summarizing, the accessory 12 comprises, from left to right in'FIGURES l and 2: va counterbored por.- tion 5 for attaching the accessory to the barrel 16; an expansion chamber 14 for providing a Vcontrolled expansion of the propellant gases; a first pair ofoppositely disi posedv vents or p orts, 16 and 32, for providing a controlled siphoning off of a portion of the propellant gases without permitting uncontrolled expansion of these gases in the atmosphere; a controlled volume chambe1j25; a second pair of oppositely disposed vents or ports, 20* and 36,.

for further siphoning offef an additional portion of the propellant gases for'permitting the first substantially 'un-- controlled ,expansion of .the propelling gases intothe atmoshpere; a controlled compression chamber l24 for compressing-the remaining propellant gases; a reduced cylindrical constriction -or throat 27 for skimming ofi any` remaining dark gases; and-a conical mouth Stl'for providing a controlled expansion of the compressed propellant Vgases as the projectile 2 leaves the accessory 12 and penen trates the atmosphere. When the projectile 2 leaves the' firearm 16, it first enters the controlled expansion chamj ber `174 wherein both the outer 'wrapping of'dark gases Vand the inner'core of whitegases undergo Va'controlled ex-ru.` f

pansion. That is toY say, the expansion chamber '14 permitsY the gases, as they leave the barrel 10, 'to ydo work which-.they would not do if they were allowed yto expand :Y

uncontrolled into the atmosphere as is normally the situation without the accessory.

Upon leaving the chamber 14, the propellant gases next reach the uniquely shaped oppositely disposed horizontally opening vents or ports 16 and 32. As the projectile passes between vents 16 and 32, a portion of the dark gases, which are predominately wrapped around the inner core of white gases, are siphoned off and horizontally emitted through the vents 1o and 32. The siphoned off dark gases thrust outwardly and a large portion thereof impinge upon the elliptoidal striking surfaces 18 and 34 of the ports 16 and 32, respectively. The impinging force of the dark gases upon the elliptoidal surfaces 18 and 34 are equal and opposite and thus impart a steadying effect to the firearm barrel and greatly reduce the undesirable barrel Vibration that is usually present when the projectile 2 penetrates the atmosphere.

The projectile 2 then passes between the oppositely disposed uniquely shaped horizontal opening vents or ports 2@ and 36. At this point substantially all of the remaining dark gases are siphoned off and, because of the increased size of the vents 2t) and 36, the propellant gases experience their first substantially uncontrolled expansion into the atmosphere. That is to say, this expansion is basically uncontrolled, at least with respect to that portion of the gases which does not impinge upon the elliptoidal surfaces 22 and 38. Thus, the siphoned off gases, which do not impinge upon the elliptoidal surfaces 22 and 38, experience a random or arbitrary expansion which is not subject to direct control or guidance by the elliptoidal surfaces 22 and 38. Some of the gases, however, impinge upon the elliptoidal surfaces 22 and 38 and apply equal and opposite pressures against the surfaces thereby imparting a further steadying effect on barrel 1t).

It is important to note at this point in the description of the operation of the present invention that the vents 16 and 32 are considerably smaller than the Vents 2@ and 36 'and that the elliptoidal surfaces 18 and Se are considerably larger than the elliptoidal surfaces 22 and 33. Further, it will be noted that the major axes of surfaces 13 and 34 are transverse to the major axes of surfaces 22 and 33. The reasons for the variable size, shape and position of the vents are as follows:

t will be recalled that when the propellant gases expand in the expansion chamber 14 they consist basically of a middle core of white gases with an outer covering of dark gases. It is essential for proper operation of the accessory according to the invention that the dark gases be removed from around the white gases before the projectile completely enters the atmosphere and proceeds in free flight. On the other hand, it is just as essential that the white gases, which are stable and of high energy, remain to the rear of and wrapped around the projectile so as to exert uniform propelling and stabilizing forces upon the projectile as it penetrates the atmosphere. Therefore, the vents must be of such a size that only the dark gases are siphoned off, and then in such a manner as to perform a useful function.

It is thus a feature of the invention that the energy of expansion of the propellant gases as they are exhausted by the Vents is to a large extent transformed into energy of motion in the projectile before they separate from the projectile. This transformation of energy has been discovered to take place predominately within a distance forward of the end of the barrel 10 of approximately the length of the projectile. Accordingly, the length of the chamber 142- of the accessory is preferably approximately equal to the length of the projectile. Vents 16 and 32 are considerably smaller than vents 20 and 36 so as to permit a greater amount of the energy of expansion to transform.z into energy of motion before the dark gases are exhausted by this rst pair of vents.

The specific shape and positioning of the elliptoidal surfaces 18 and 3d are desirable for maximum stabilization and utilization of the energy in the dark gases. The.

6 elliptoidal surfaces 18 and 34 are preferably larger than surfaces 22 and 38 since less dark gases are exhausted at vents 16 and 32 than at vents 2@ and 3d and this larger surface provides a greater area for the gases to impinge upon so as to utilize the energy of the gases to perform a maximum stabilizing function.

After passing the second pair of vents 20 and 36 the projectile 2 enters the compression chamber 2d and then the cylindrical constriction or throat portion 27. By the time the rear end of the projectile reaches the chamber 24 the gases which surround and follow it are almost completely white stable gases. That is to say, the vents 16, 32, 2t) and 36 have substantially removed the dark unstable gases from around and behind the projectile. The diverging conical shoulder portion 26, which connects inner wall 13 and throat wall 23, has a dual purpose. First, the diverging shoulder 26 is designed to compress the remaining white gases and skim olic any last remnants of the dark gases which were not siphoned off by the vents thereby allowing only the white gases to have any effect on the projectile as it exits from the mouth 30. Second, the forward pressure caused when the gases impinge on the diverging shoulder 26 help to reduce recoil by counter action or reaction.

The projectile 2 next exits through the mouth or coneshaped opening Si) and the white gases about the projectile experience a controlled expansion along the cone-shaped surface of the mouth 3d. The expanding white gases exert a uniform pressure against the cone-shaped surface of the mouth 3d and tend to balance the forward thrust exerted when the gases impinged on the elliptoidal surfaces 18, 34, 22 and 38 and diverging shoulder 26 thereby imparting a further steadying effect to the firearm barrel 1d. In addition, the surface 30 tends to decrease barrel vibration, reduce muzzle ash and suppress muzzle blast.

lt should be noted that the Vents 16, 32, 22 and are displaced 189 from one another and open horizontally or transversely to the longitudinal axis of the accessory 12. This specific positioning of the vents is important in that the exhausted dark gases are propelied or directed to either side of the accessory 12. As a result, not only is a stabilizing effect produced, but when the firearm is fired from a prone, sitting or even standing position, the exhausted dark gases do not pick up debris from the ground under the gun barrel or accessory 12 and thereby hamper the visibility of the person discharging the firearm or even injure such person. ln addition to this, if vents were provided facing both upwardly and downwardly or in a nonhorizontal direction, the reaction or kick of the barrel 1t) would be greater on the underside than on the upper side. The reason for this is that the gases emitted downwardly would experience a greater reaction force when they strike the ground or earth below the gun than the gases emitted upwardly. Thus, the horizontal exhausting of the dark gases by the Vents is an essential feature of the present invention.

As one example of specific dimensions for a preferred embodiment of a firearm accessory constructed in accordance with the present invention, the following dimensions may be utilized.

(l) The projectile diameter is approximately .224 inch.

(2) The projectile length is approximately 3 times its diameter. s

(3) The outside diameter of barrel 1@ is .626 inch.

(4) The outside diameter of accessory 12 is approximately .872 inch.

(5) The inside diameter of accessory 12 is approximately .520 inch. l

(6) The length of the accessory 12 is approximately 3 inches.

(7) The Vents 16 and 32 have elliptoidal side walis and .a circular central opening.

approximately (S) The diameter of the circular central opening of vents 16 and 32 is approximately .2031 inch,

(9) The elliptoidal side walls 18 and 34 of vents lo and 32 have a major axis of approximately .750 inch and a minor axis of approximately .406 inch.,

(10) Vents 20 and 36 have elliptoidal side walls and an elliptical central opening.

(11) The elliptical central opening of vents 20 and 36 have a major axis of approximately .8125 inch and a minor axis of approximately .625 inch.

(l2) The elliptical side walls of vents 20 and 36 have a Width of approximately .0625 inch.

(13) The diameter of throat 27- is approximately .394

Y inch (the projectile 2 is approximately Z/a the sizeof throat 27 (14) The length of throat 27 is approximately .200 inch.

(15) The mouth 3f) is a frustum of a cone having a length of approximately .366 inch. It will be apparent from the foregoing that the firearm accessory of the present invention is low in cost, rugged in construction, and requires practically no maintenance. The use of uniquely shaped and horizontally positioned vents impart a steadying effect upon the barrel of the firearm and considerably reduces vibration. In addition, the uniquely positioned expansion and compression chambers of the accessory control and stabilize the propellant gases so as tok impart a stabilizing effect upon the projectile, increase its accuracy, range and velocity, reduce recoil and decrease substantailly all barrel vibration. Further, the elliptoidal gas impinging surfaces of the vents and the diverging throat surface further provide barrel stabilization, reduce barrel vibration and provide increased accuracy, velocity and range of the projectile by absorbing and uni- `formly controlling the energies of the vented propellant gases.

The firearm accessory of the present invention is equally applicable to all kinds of firearms, including hand and shoulder firearms, machine-guns and other ordnance weapons and may be provided both as a removable accessory and as an integral part of the firearm.

The invention maybe embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

, said barrel, said housing defining an end chamber spaced from the ried portion of said barrel and connected to said central chamber and having a diameter smaller than the diameter of `said central chamber, a first pair of oppositely disposed ports spaced from said riiied portion of Y said barrel, and a secondA pair of oppositely disposed ports of a larger area than said first pair disposed between said first pair of ports and said end chamber, the ports in each said pair having walls flaring outwardly from the interior Y than'the diameter of the'rified portion of saidV barrel and cs connected to the chamber defined by theried portion of said barrel, said housing defining an end chamber spaced from the rifled portion of said barrel and connected to said central chamber and having a diameter smaller than the diameter of said central chamber, a first pair of oppositely disposed ports spaced from said filled portion of said barrel, ,and ta second pair of oppositely disposed ports disposed between said first pair of ports and said end chamber, the ports in each said pair being centered on faxes perpendicular to a plane containing said trigger, each port having an inner peripheral edge and an outer peripheral edge with the peripheral length of the outer peripheral edge longer than the peripheral tlength of the Vinner(peripheral edge, said housing defining a solid peripheral wall at positions lying in tand immdiately adjacent said plane containing said trigger.

3. ln a firearm having a rified barrel and a trigger, tan elongated housing extending from the firearm barrel and having a central cylindrical chamber of a diameter greater than the diameter of the riiied portion of said barrel and connected to the chamber defined by the riiled portion of said barrel, said housing defining an end charnber spaced from the rified portion of said barrel and connected to said central chamber and having a dirameter smaller than the diameter of said central charnber, a first pair of oppositely disposed ports spaced from said rified portion of said barrel, and a second pair of oppositely disposed ports disposed between said iirst pair of ports and said end chamber, the ports in each said pair being centered on axes perpendicular to a plane containing said trigger, each port having an inner peripheral edge and an outer peripheral edge with the peripheral length of the outer peripheral edge longer than the peripheral length of the inner peripheral edge, the ratio of the length of the outer peripheral edge to the length of the inner peripheral. edge of the ports in said first pair being greater than the corresponding ratio of the ports in said second pair, said housing defining a solid peripheral wall tat positions lying in and immediately adjacent said plane containing said trigger.

4. In a firearm having sa rified barrel and' a trigger, an elongated housing extending fnom the firearm barrel and having a central cylindrical 4chamber of a diameter greater than the diameter of the ried por-tion of said barrel and connected 4to the chamber defined by the rifled portion of said barrel, said housing defining an end chamber spaced from the rified portion Vof said barrel and connected to said central chamber tand having aV diameter smaller than the diameter of said central chamber, a first pair of oppositely disposed ports spaced from said ritled portion of said barrel, and a second pair of oppositely disposed ports disposed between said. first pair of ports and said end chamber, the ports in each said pair being centered ton axes perpendicular to a plane containing said trigger, each port having van inner peripheral edge andanV outer peripheral edge with the peripheral length of the outer peripheral edge longer thanrthev peripheral length ofthe inner peripheral edge, the ratio of thelength of the outer peripheral edge to the length of the inner peripheral edge of the ports in said first pair being greater lthan the corresponding ratio of the ports in said'second said second pair being generally elliptical, said housing* defining a solid peripheral wall at positionsrlying in and immediately :adjacent said plane containing said trigger.

Y 5. A firearm accessoryfor a firearm having a barrel' containing a bore, Vcomprising, a housing defining a central cylindricalV chamber adjoining-a reduced diameter cham-VV ber at one Yend of said housing opening to the atmosphere,

the other end'of said housing being Yopen and adapted for Yattachment to the barrel lof said firearm, the diameter of said central chamber being greater than the diameter ofV the bore of said firearm, a first pair of oppositely disposed ports in said housing centrally disposed about an taxis perpendicular to the axis of said bore, and a second pair of oppositely disposed ports in said accessory disposed centrally about an axis parallel to the axis of said first pair of ports, said first pair of ports being of smaller area than said second pair of ports and disposed between said second pair of ports and said other end of said housing, each port having an inner peripheral edge and an outer peripheral edge, the ratio of the length of the outer peripheral edges to the length of the inner periphenal edges of the ports in said first pair being greater than the corresponding ratio of the ports of said second pair.

6. A firearm accessory for a firearm having a barrel containing a bore, comprising, a housing defining a central cylindrical chamber adjoining a reduced diameter chamber at one end of said housing opening to the atmosphere, the other end of said housing being open and adapted for attachment to the barrel of said firearm, the diameter of said central chamber being greater than the diameter of the bore of said firearm, a first pair of oppositely disposed ports in said housing centrally disposed about an axis perpendicular to the axis of said bore, and a second pair of oppositely disposed ports in said accessory disposed centrally about an axis parallel to the axis of said first pair of ports, said first pair of ports being of smaller area than said second pair of ports and disposed between said second pair of ports and said other end of said housing, said axis of said first pair of ports being removed from said other end of said housing by a distance at least as great as the length of the projectile fired by said firearm.

7. A firearm accessory for a firearm having a barrel containing a bore, comprising, a housing defining a central cylindrical chamber adjoining a reduced diameter chamber at one end of said housing opening to the atmosphere in expanding conical shape, the other end of said housing being open and adapted for attachment to the barrel of said firearm, the diameter of said central chamber being greater than the diameter of the bore or" said firearm, a first pair of oppositely disposed ports in said housing centrally disposed about an axis perpendicular to the axis of said bore, and a second pair of oppositely disposed ports in said accessory disposed centrally about an axis parallel to the axis of said first pair of ports, said first pair of ports being of smaller area than said second pair of ports and disposed between said second pair of ports and said other end of said housing.

8. A firearm accessory for a firearm having a barrel containing a bore, comprising, a housing defining a central cylindrical chamber adjoining a reduced diameter chamber at one end of said housing opening to the atmosphere, the other end of said housing being open and adapted for attachment to the barrel of said firearm, the diameter of said central chamber being greater than the diameter of the bore of said firearm, a rst pair of oppositely disposed ports in said housing centrally disposed about an axis perpendicular to the axis of said bore, and a second pair of oppositely disposed ports in said accessory disposed centrally about an axis parallel to the axis of said first pair of ports, said first pair of ports being of smaller area than said second pair of ports and disposed between said second pair of ports and said other end of said housing, each port having an inner peripheral edge and an outer peripheral edge, the ratio of the outer to the inner peripheral edges of the ports in said first pair being equal to one another and the corresponding ratio of the ports in said second pair being equal to one another.

9. A firearm accessory for a firearm having a barrel containing a bore, comprising, a housing defining a central cylindrical chamber adjoining a reduced diameter chamber at one end of said housing opening to the atmosphere, the other end of said housing being open and adapted for attachment to the barrel of said firearm, the diameter of llt) said central chamber being greater than the diameter of the bore of said firearm, a first pair of oppositely disposed ports in said housing centrally disposed about an axis perpendicular to the axis of said bore, and a second pair of oppositely disposed ports in'said accessory disposed centrally about an axis parallel to the axis of said first pair of ports, said first pair of ports being of smaller area than said second pair of ports and disposed between said second pair of ports and said other end of said housing, each port having an inner peripheral edge and outer peripheral edge, the ratio of the length of the outer peripheral edges to the length of the inner peripheral edges of the ports in said first pair being greater than the corresponding ratio of the ports of said second pair, the portions of said housing between said peripheral edges of said ports forming a plurality of striking surfaces which are frustums of hollow elliptoids; said striking surfaces which circumscribe said first pair of ports having an inner circular edge and an outer elliptical edge; and said striking surfaces which circumscribe said second pair of ports having inner and outer elliptical edges.

10. A firearm accessory in accordance with claim 9 wherein: said elliptical outer edges of said striking surfaces which surround said first pair of ports have a major axis transverse to the axis of said accessory; and said elliptical outer and inner edges of said striking surfaces )which surround said second pair of ports have a major axis parallel to the axis of said accessory.

l1. A firearm accessory for attachment to the muzzle end of the barrel of a firearm, comprising: a housing defining an expansion chamber located forward of said end of said barrel for controlling the propellant gases which surround and follow a projectile when it is fired by said firearm; said housing having an inner diameter which is larger than the inner diameter of said barrel and smaller than the outer diameter of said barrel so as to form said expansion chamber when said accessory is attached to said muzzle end of said barrel; at least two pairs of horizontally positioned oppositely disposed ports for removing a portion of said expanded propellant gases before said projectile penetrates the atmosphere; the first pair of ports being circular and having a diameter substantially smaller than the diameter of said expansion chamber and the second pair of ports being elliptical and having a minor axis substantially the same size as the diameter of said expansion chamber; at least two pairs of striking surfaces which respectively circumscribe said pairs of ports and upon which said removed portion of said expanded propellant gases may impinge for stabilizing said firearm; said striking surfaces being frustums of hollow elliptoids; said striking surfaces which circumscribe said rst pair of ports each having an inner circular edge and an outer elliptical edge; said outer elliptical edges of said striking surfaces which circumscribe said first pair of ports having a major axis transverse to the axis of said accessory; said striking surfaces which circumscribe said second pair of ports having inner and outer elliptical edges; said elliptical edges of said striking surfaces which surround said second pair of ports having a major axis parallel to the axis of said accessory; a compression chamber located forward of said vents and striking surfaces for compressing the remaining expanded propellant gases; said compression chamber being a frustum of a cone having its larger opening connected to the inner wall of said accessory, and its axis collinear with the axis of said accessory; a cylindrical throat located forward of said compression chamber for removing a portion of said compressed propellant gases; said cylindrical throat having an inner diameter slightly larger than the outer diameter of said projectile and one end connected to the smaller opening of said compression chamber; a conical mouth located forward of said throat for controlling the expansion of said compressed propellant gases as said projectile leaves said accessory and penetrates the atmosphere; and said conical mouth being a frustum of l 1 a cone having its smaller opening connected to the other end of said cylindrical throat, its larger opening forming the forward outer edge of said accessory, and its axis collinear withY the axis of said accessory.

References Cited in the le of this patent UNITED STATES PATENTS 2,212,684` Hughes Aug. 27, 1940 2,212,686Y Hughes Aug. 27, 1940 2,322,370v Lance June 22, 1943 12 2,828,569 Steane Apr. 1, 1958 2,852,983 Netzer Sept. 23, 1958 FOREIGN PATENTS 5 314,842 Germany Oct. 20, 1919 510,683 France Dec. 9, 1920 825,016 France Nov. 27', 1937 OTHER REFERENCES Muzzle Brakes (Harrison), American Rileman, May 10 1957, pages 28-30. Y

UNITED STATES PATENT OFFICE CERTIFICATE. Nor CORRECTION Patent No., 3, 155,003 November 3, 1964 John H. Ruth 1t is hereby certified that error appears in the above numbered patent requiring: oorrectio'nand that the saidLett'ers Patent should read as corrected belowy Column 2, line Y.2, befxore "projectile" insert the column 5, line 19, for horizontelfread horizontally Signed and sealed this 1th day of May 1965.

.(fSEAL) Attest:

ERNEST SWIDER EDWARD J. BRENNER 4 Attesting Officerl Commissioner of Patents ITED STATES PATENT OFFICE CERTIFICATE-o1 CoRRECTIoN Pei-,ene No. 3,155,003 November 3, 1964 John H. Ruth lt ehereby certified that error appears vin the above numbered pat-` ent reqlrng correetio'nand that the saidLetter-s Patent shouldread ,as

corrected below .I

Column 2, line l2, before "projectile" insert -F the column 5, line 19, for' "horizontal," read horizontally signed end eee1ed this L11-,h dey of Mey 1965.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J.. BRENNER Attest-ing Officer ACommissioner;,of Patents 

1. IN A FIREARM HAVING A RIFLED BARREL AND A TRIGGER, AN ELONGATED HOUSING EXTENDING FROM THE FIREARM BARREL AND HAVING A CENTRAL CYLINDRICAL CHAMBER OF A DIAMETER GREATER THAN THE DIAMETER OF THE RIFLED PORTION OF SAID BARREL AND CONNECTED TO THE CHAMBER DEFINED BY THE RIFLED PORTION OF SAID BARREL, SAID HOUSING DEFINING AN END CHAMBER SPACED FROM THE RIFLED PORTION OF SAID BARREL AND CONNECTED TO SAID CENTRAL CHAMBER AND HAVING A DIAMETER SAMLLER THAN THE DIAMETER OF SAID CENTRAL CHAMBER, A FIRST PAIR OF OPPOSITELY DISPOSED PORTS SPACED FROM SAID RIFLED PORTION OF SAID BARREL, AND A SECOND PAIR OF OPPOSITELY DISPOSED PORTS OF A LARGER AREA THAN SAID FIRST PAIR DISPOSED BETWEEN SAID FIRST PAIR OF PORTS AND SAID END CHAMBER, THE PORTS IN EACH SAID PAIR HAVING WALLS FLARING OUTWARDLY FROM THE INTERIOR OF SAID HOUSING AND BEING CENTERED ON AXES PERPENDICULAR TO THE LONGITUDINAL AXIS OF SAID BARREL AND PERPENDICULAR TO A PLANE CONTAINING THE TRIGGER OF SAID FIREARM, SAID HOUSING DEFINING A SOLID PERIPHERAL WALL AT POSITIONS LYING IN AND IMMEDIATELY ADJACENT SAID PLANE CONTAINING SAID TRIGGER. 